alert tcp-pkt $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET MALWARE implant.js Linux Beacon Check-in";
flow:established,to_server;
flowbits:isset,ET.implantjs.syn;
dsize:1;
content:"|c1|";
reference:url,github.com/captainGeech42/implant.js;
reference:url,districtcon.org/bios-and-talks-2025/implantjs-modular-malware;
classtype:trojan-activity;
sid:2060255; rev:3;
metadata:affected_product Linux, attack_target Client_Endpoint, tls_state plaintext, created_at 2025_02_21, deployment Perimeter, deployment Internal, malware_family implant_js, performance_impact Moderate, confidence High, signature_severity Major, tag c2, updated_at 2026_05_21, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
target:src_ip;
)